It appears that the announcement of Plants vs Zombies: Garden Warfare 3 has been leaked. This comes from a description of Plants vs. Zombies: Garden Warfare Volume 2 comic book appeared on its Amazon product page. The description reads as follows..

Garden Warfare Returns to Neighborville!

Paul Tobin returns to write the official comic book bridge between video games PvZ: GW2 and PvZ: GW3 with Tim Lattie returning to deliver artwork!

Just when you thought Neighborville was safe, the Garden Warfare is back on! Zombies have taken over and forced neighborhood defenders Nate, Patrice, and their fearless plants back on their heels! Not all hope is lost however when an unlikely plant hero comes to the rescue with the fate of Neighborville at stake!